The present invention pertains to a therapeutic chair, and, more particularly, to a unique seat design and universal seat connector that reduces pressure on the back of the legs, especially the veins, and facilitates therapeutic exercise when seated.
Mobile tissue, and, in particular, the spine, is susceptible to a variety of disorders resulting from active misuse and sedentary neglect. It has been shown that approximately 90% of chronic pain is located in the musculoskeletal system, with the prevalence of pain in individuals up to 59 years of age commonly occurring in the head, neck, shoulders, low back, legs, and pelvis. Some form of acute and chronic spinal pain will affect almost 80% of individuals in the western world. Musculoskeletal conditions have been recognized as a major cause of health and economic problems, with spine-related disorders second only to the common cold as a reason for absence from work.
Sleep disorders are also related to back pain, such as restless leg syndrome, periodic limb movement disorders, and sleep apnea. Backaches and leg pains are considered a major cause of sleep deprivation and have been attributed to a substantial loss of work productivity and work-related injuries.
While it has been assumed that lifting and bending accidents were the common cause of back injuries, approximately 80% of the U.S. population now have sedentary jobs requiring them to sit for up to eight hours per day. Factoring in the additional sitting time for work-related travel and resting or watching television, individuals may be sitting up to fifteen hours per day. While bending and lifting accidents can occur suddenly with known causes, a sedentary worker""s back-related problems will occur gradually with no apparent identifiable cause.
After about age 12, the vascular supply system to spinal disks will begin to atrophy. The aging disks need just as much daily nutrition intake, metabolic waste, and algogenic inflammatory exudate elimination as they did before becoming avascular. It is generally accepted that a daily full range of motion, identified as xe2x80x9cosmosis and imbibitionxe2x80x9d is absolutely essential for daily metabolic interchange. That is, nutrition intake and elimination of waste products must occur in order to maintain healthy, well-hydrated spinal disks, ligaments, and tendons.
In contrast, it has been found that up to 500 days is required for metabolic interchange by patients who are sedentary and patients who do not engage in a daily full-range spinal workout. The full-range workout is necessary to mix the glucosaminoglycans, chondroitin sulfate, and the proteoglycan aggregates that then nourish the disks and other avascular tissues.
Clinical observations have established the deleterious effects of the immobilization of joints and tissues in patients. It has also been observed that early active motion as opposed to prolonged immobilization of diseased and injured parts provides beneficial local effects. In addition, active and passive motion of the spine and extremities will reduce a patient""s susceptibility to necrosis resulting from prolonged immobilization.
Thus, the best treatment and maintenance of healthy mobile tissue, such as the spine, is motion. It is well known that the biomechanics of the spine involve six degrees of motion (flexion, extension (right and left), rotation (right and left), lateral bending, and long-axis distraction and compression (load/unload cycling)).
During the normal gait or walking cycle, the spine is in a lordotic position, wherein portions of the spine receive a circumductive load-and-unload force. This cycle occurs each time a step is taken as gravity forces the body downward. The pumping action creates a load/unload cycle along with a slight rotational component as the arms swing and the legs alternately step. Patients confined to wheelchairs, those suffering from spinal injuries, or otherwise healthy individuals subjected to prolonged immobilization are unable to actively put the spinal column in motion and achieve the required circulation of blood and intercellular fluids through the spinal region, including the disks and legs.
One attempt to provide motion to seated workers is described in U.S. Pat. No. 5,113,851 issued to Gamba on May 19, 1992 for a chair equipped with a swinging seat. Gamba teaches the mounting of a seat to a base through an articulated ball joint mechanism with movement induced by a motor through a gear train assembly. Hence, Gamba provides passive motion, i.e., motion produced by an external force, using a complicated, expensive, and cumbersome motor and gear train assembly. Moreover, the articulated ball joint assembly provides no structure for resisting movement of the seat or maintaining the seat in a relatively horizontal position when no force is applied or when not in use. In addition, the seat of Gamba provides no relief for pressure on the legs of a user.
The present invention is directed to a therapeutic chair having a seat, a base for supporting the seat on a surface, and a seat support mechanism configured to couple the seat to the base and enable the seat to rock in any direction with respect to the base and to resist rocking of the seat. Ideally, the seat support mechanism returns the seat to a starting position, such as a horizontal position, when no force is applied or when not in use.
In accordance with another aspect of the present invention, the seat support mechanism includes a first support member configured for mounting to one of either the seat or the base and a second support member configured for attachment to the other of the seat and the base and further configured to receive the first support member in slidable engagement, the second support member including at least one resilient member configured to urge the first support member into alignment with a longitudinal axis of the second support member.
In accordance with a further aspect of the present invention, the first support member is a post having a longitudinal axis and the second support member is a housing with a longitudinal axial bore defining an interior, and further including at least one resilient member mounted in the housing interior with a central opening that is sized and shaped to receive the post.
In accordance with yet another embodiment of the present invention, a therapeutic chair is provided having a seat and a base for supporting the seat on a surface, the seat having a substantially triangular planform shape with an apex portion configured to be straddled by a user""s legs and a base portion configured to support the user in a seated position. Ideally, the apex portion of the seat is upturned, as are first and second corners of the base portion.
In accordance with still yet another aspect of the present invention, the seat has a top surface and a bottom surface, and the top surface has a dished configuration such that the apex portion and first and second comers of the base portion are upturned.
In accordance with yet a further embodiment of the present invention, a therapeutic chair is provided having a hydraulic, adjustable-height seat with 360 degrees of rotation, 40 degrees of side-to-side flexion, and 35 degrees of front-to-back flexion on a universal-type joint to facilitate all possible combinations of exercise motion.
As can be readily appreciated from the foregoing description, the therapeutic chair of the present invention has a pyramid-shaped seat. The top of the pyramid faces forward. The seat rests on a universal joint that enables controlled motion by a user in all directions as the user moves, while simultaneously ensuring stability of the arms, back, and chair base. The unique seat is designed for freedom of leg motion and blood circulation. This design combined with user-controlled motion allows for continuous spinal, low back, and leg macro and micro-motions to prevent accumulative trauma injuries to the back, relief for aching legs, and prevention of varicose veins. The arms of the therapeutic chair are adjustable to three inches higher than ordinary chair arms, which the user""s arms to rest when working. The higher arms minimize the user""s arm weight, thus not only preventing but also relieving chronic aching in the neck, upper mid back and shoulders, as well as carpal tunnel aggravations of the wrist and hands.
The back of the chair is not as tall as other chairs, allowing for support of the user""s rib cage and the upper part of the low back without interfering with breathing. The back and the seat of the chair are adjustable for tilting backward or forward in combinations for the comfort of the user. The seat bottom may be tilted forward while the chair back is tilted backwards, or vice versa. In addition, the chair sits on an adjustable-height gas cylinder.